Answer: a
Explanation: To find the surface area of an object you add up all the areas. ( but I’m pretty sure there’s also a formula )
To make the area of one rectangle you multiply the length and width, which in this case is 5 and 10 — you would get 50. Now multiply that by 3 because there are 3 rectangles.
50 * 3 = 150
The total area of the rectangles are 150cm^2
Now let’s find the area of a triangle. The formula for finding the area of a triangle is A = 1/2bh. Let’s substitute in our numbers
A = 1/2 * 4 * 5
A = 10
Multiply by 2 to find the total area of both triangles.
2 * 10 = 20
The total area of the triangles are 20cm^2.
Lastly, add up the areas of the triangles and rectangles
20 + 150 = 170cm^2
So your answer is a, 170cm^2